Big providers use NAT to squeeze little ISPs

  I will restart my question as such:

  It is my understanding that;

  One of your principal objections to NAT boxes is that they are
  motivated by technical and trade practices you find dishonest.

  Please define and expound.

My principal objection to NAT is that it breaks lots of things, including
some servers, that customers want to put on their networks.

At the PROVIDER level, especially at the level we run at, there is no NAT
box made fast enough to do the job regardless of price.

  Do you really think that big ISP puts in /19 filters to make life
  hard for the "little guy" at the bottom of the "money pile"?


As long as a provider can get their own /19 I have no problem with
prefix filtering at the /19 level.

The problem comes about when big ISPs filter at /19s *AND* the allocators
of space refuse to give ISPs /19s.

I don't think either of these is in danger of happening. I certainly don't
hear anyone complaining that their Ciscos are going to fall over
due to routing table growth and as we all know, there are other big router
boxes very near release that won't have this problem.

As for allocation policies, these are pretty much in the collective hands
of the network operators now. This means it is extremely unlikely that
they will do something that is dumb from an operational point of view.
Note that the only significant event related to this was when RIPE's
allocation policies conflicted with Sprint's filters and it was worked out
to the general benefit of network operators.

The main problem with filters right now is that there isn't enough of
them, i.e. we need more widespread deployment of bogon filters.

Michael Dillon - Internet & ISP Consulting
Memra Software Inc. - Fax: +1-250-546-3049 - E-mail: